The use of voltage signal line drivers in telecommunications is well-known. For example, the article "A Single-Chip Digital Signaling Interface for the DS1 Intraoffice Environment," by J. P. Hein and R. J. Starke, published at the 1989 IEEE International Solid State Circuits Conference and herein incorporated by reference, describes a voltage signal line driver as part of the digital signaling interface. Other articles include "A 1.544-Mb/s CMOS Line Driver for a 22.8-Ohm Load," by H. Herrmann and R. Koch, published in the IEEE Journal of Solid-State Circuits, Vol. 25, No. 3, June 1990, and "A Monolithic Line Interface Circuit For T1 Terminals," by K. J. Stern, N. S. Sooch, D. J. Knapp, and M. A. Nix, published at the 1987 IEEE International Solid-State Circuits Conference, both of which are herein incorporated by reference.
In telecommunications applications, signaling standards, such as the North American DS1 standard, provide for output voltage pulses having multiple voltage levels or amplitudes substantially in accordance with a predetermined output voltage pulse template. See, for example, the AT&T-Microelectronics March 1992 Datasheet for the T7290 DS1/T1/CEPT Line Interface, herein incorporated by reference. In a low-voltage environment, such templates may be difficult to achieve at least in part due to undesirable variations in the amplitude of the output voltage signal. A need, therefore, exists for a voltage signal line driver that exhibits less variability in the output voltage signal amplitude of the output voltage signal produced by the voltage signal line driver, especially for low-voltage environments.